The purpose of this project is to study the chemical and physical properties of proteoglycans, primarily those derived from cartilaginous tissues. Topics of present interest include: 1) chemistry of proteoglycans isolated from bovine hyaline cartilages and from the Swarm rat chondrosarcoma, 2) mechanisms of proteoglycan aggregation and interaction with hyaluronic acid, 3) biosynthesis of the protein core of proteoglycans by chondrocyte cultures, 4) changes in proteoglycan structure during chondrogenesis and maturation of chick limb bud chondrocyte cultures, 5) characteristics of proteoglycans derived from follicular fluid during follicular development.